Last March, a Russian arms maker invited a delegation of Iranians to a VIP shopping tour of its weapons factories. The 17 visitors were treated to lunches and cultural shows and, on the final day, toured a plant that makes products long coveted by Tehran: advanced Russian air defense systems for shooting down enemy planes.

Israelis awaited word on how Prime Minister Benjamin Netanyahu would respond to Iran's first-ever direct attack as international pressure for restraint grew amid fears of an escalation of the conflict in the Middle East.

The United Nations nuclear watchdog chief said on Monday he is concerned about Israel possibly targeting Iranian nuclear facilities, but that International Atomic Energy Agency (IAEA) inspections of Iranian facilities would resume on Tuesday.

Israel's military chief said on Monday his country would respond to Iran's weekend missile and drone attack amid calls for restraint by allies anxious to avoid an escalation of conflict in the Middle East.

Russia said on Sunday it was extremely concerned by Iranian strikes on Israel and called on all parties to exercise restraint, but said tensions would remain high until the conflict between Israel and the Palestinians was resolved.

The prospect of Israeli retaliation against Iran for its drone and missile attack at the weekend has alarmed many Iranians already facing economic pain and tighter social and political controls after protests in 2022-23.

The multilateral effort to repel the Iranian strike could be an opportunity for Israel to return to the international fold after widespread condemnation of its war in Gaza.